This invention relates to an improved adaptor assembly that releasably connects a fiber optic waveguide to a fiber optic illuminator and protects the fiber optic waveguide from contamination during use and handling.
Many types of light source systems have been developed to couple light from a high intensity light source, such as an arc lamp, into a light pathway comprising a single optical fiber or a fiber optic bundle constructed from a light conducting material such as glass or plastic. Light energy carried through the optical fibers is used in various industrial, commercial, and medical applications. For example, light energy carried through optical fibers is used in the medical field to provide illumination to various medical components, including headlights, endoscopes, and assorted surgical instruments.
FIG. 1 illustrates a typical fiber optic illumination system used in medical and industrial applications. The fiber optic illumination system includes an optical light source system 2 having a light source 3 and an optical system 4 for collecting and focusing the light emitted by the light source. An illumination device 8, such as an endoscope, is connected to the light source system 2 via an optic fiber light guide 6 coupled to the light source system 2 by a proximal connector 5. The optic fiber light guide 6 may be a fiber optic bundle or a single optic fiber. Typically, the proximal connector 5 is removable from the light source system 2 in order to increase the convenience of using the illumination device 8. For instance, the same light source system 2 may be used with multiple, different illumination devices 8.
The light source 3 is typically a light source having an envelope. Preferably, the light source 3 comprises an arc lamp such as a xenon lamp, a metal-halide lamp, a HID lamp, or a mercury lamp. The arc lamps are desirable because they produce light energy of high intensity. For certain applications, filament lamps, e.g., halogen lamps, can be used, provided the system is modified to accommodate the non-opaque filaments of the lamp. Typically, the positioning of the output waveguide is slightly altered so that the proximal, input end of the output waveguide is not in the shadow of the filament.
The light source system may further include various optical collection and condensation systems (not illustrated) that employ various lenses, mirrors, and filters. For example, it is well known in the art to use ellipsoidal reflectors to condense the light energy and to use parabolic reflectors to collimate the light energy. The various components of the optical collection and condensation system may be combined to produce desired results. Likewise the various components of the optical collection and condensation system may be positioned in numerous on-axis and off-axis arrangements as needed to produce desired illumination.
Traditional types of proximal connectors systems include a fixed adaptor, a turret adaptor, and a universal adaptor. However, these traditional proximal connectors are bulky and heavy. As a result, when a traditional proximal connector is removed from the light source system 2, the weight of the proximal connector stresses the optic fiber light guide 6 unless carefully handled.
Another disadvantage to the traditional proximal connector is that it positions the proximal end of the optic fiber light guide 6 approximately at a point inside the light source where the light is most concentrated. Although this positioning of the optic fiber light guide 6 maximizes the collection of light energy, energy from the light source 3 is absorbed and accumulated by the connector and the light guide 6 as heat energy. As a result, the traditional proximal connector often becomes very hot, which is a hazard to people working with the optical illumination system. The heating of the proximal connector also degrades the performance of the system by distorting the transmitted light energy and potentially damaging the optic fiber light guide 6.
A further disadvantage to the traditional proximal connectors is their relative high costs. In particular, the cost for the traditional proximal connector becomes prohibitive in applications where the optic fiber light guide 6 is intended to be disposed after a single use, such as endoscopic medical procedures in which the optic fiber light guide 6 is inserted into a human body.
In response to these disadvantages of traditional proximal connectors, alternative proximal connectors have been developed. For example, U.S. Pat. No. 5,640,478 discloses an optical system, illustrated in FIGS. 2-3, having a cone-shaped proximal connector 30 that connects to a correspondingly shaped opening 24 in a receiving structure 26 in the house 28 for the light source system 2. With this connection system, heat absorbed by the proximal connector 30 is dissipated into the receiving structure 26, thus preventing the undesired accumulation of excessive heat energy in the proximal connector 30. Furthermore, a first conical surface 32 and a second conical surface 38 properly position the proximal end 33 of connector 30 in the receiving structure 26 for receiving light energy from a light source. In this position, the first conical surface 32 and the second conical surface 38 contact an inner surface 44 of the housing 26, but the proximal end 33 is left exposed to an opening 46 in the receiving structure 26 to receive light energy. The proximal connector 30 further contains a detente 36 for engagement to a retaining formation 42, such as a spring-biased ball plunger. Although held in position to receive light energy, the proximal connect may still move radially to compensate for any twisting of the optic fiber light guide 6. As a result, the proximal connector 39 may be small and light, yet still securely position a proximal end of optic fiber light guide 6 in a desired location for receiving light energy from the light source system, as illustrated in FIG. 3.
Similarly, U.S. Pat. No. 5,764,837 (xe2x80x9cthe ""837 patentxe2x80x9d) also provides a proximal connector system having a cone-shaped proximal connector 50 that connects to a correspondingly shaped opening in the light source system. As illustrated in FIG. 4, the ""837 patent the connector 50 has a built-in fiber optic element 51 that extends from a proximal tip 53 of the proximal connector 50 to a proximal end 57 of the optic fiber light guide 56. The proximal end 57 of the optic fiber light guide 56 is contained in a bore 61 in a fiber cable connector 60. On a distal end of the proximal connector 50 is a fiber cable adapter 58 having an opening 59 adapted to receive the fiber cable connector 60. Light energy exits the light source system via the fiber optic element 51, which directs light energy to the output optic fiber light guide 56. As a result of this connection system, the proximal end of the optic fiber light guide 6 is moved away from area of light and heat concentration within the light system. This placement decreases heat accumulation in the optic fiber light guide 56, thereby improving the performance and durability of the fiber optic illuminator system.
Furthermore, the adapter case 58 in the ""837 patent accepts a detachable connector 60 that secures the proximal end of the optic fiber light guide 56. The adapter case 58 easily detaches from a first detachable connector 60. Therefore, this system facilitates the use of a single-use, disposable optic fiber light guide 56 by allowing the same, relatively expensive proximal connector 50 with different optic fiber light guides 56.
Overall, the proximal connector of the ""837 patent has a simple, light design that provides a secure connection to the light source system while allowing connection to different optic fiber light guides and protecting the proximal connector from heat accumulation. However, the proximal connector assembly 50 of the ""837 patent has the disadvantage that it must closely mate with detachable connector 60 in order to achieve a reliable connection and a proper optical passageway. Thus, the proximal connector assembly 50 has little ability to accept differently configured optic fiber light guides. This limitation is significant in that various manufacturers produce optic fiber light guides with detachable connectors of differing physical configurations.
In response to this deficiency, U.S. Ser. No. 09/532,300 provides a special proximal connector assembly that is able to accept output from several different detachable connectors for optical waveguides. In particular, the proximal connector assembly provides several connection points and connection structures to allow the use of the different detachable connectors. The subject matter in U.S. Ser. No. 09/532,300 is herein incorporated by reference in full.
However, all of the known proximal connectors expose the proximal, input end of the optic fiber light guide during regular use, thereby allowing the proximal end of the optic fiber light guide to collect and accumulate dirt and debris. The dirt and debris on the optic fiber light guide 6 impede the performance of the optical system by disrupting the passage of the light energy to the fiber light guide 6. Furthermore, as the dirt and debris absorb optical energy, they can become very hot and potentially damage or destroy the optic fiber light guide.
As a result, there exists a present need for an improved optical connection system that prevents potentially damaging contamination to the optic fiber light guide while preserving the advantages of lowcost usage, proper alignment, and heat sinking, ease of handling, and adaptability for use with numerous types optical light guides.
The above-described need is addressed in accordance with the general principles of the present invention. The present invention provides a connector assembly comprising (1) a first adapter that releasably connects to the light source and transmits optical energy received from the light source along a first optical waveguide; (2) a second adapter that releasably connects to the first adapter to receive and transmit optical energy along a second optical waveguide; and (3) an output optical waveguide that receives the transmitted optical energy from the second waveguide and has a proximal connector adapted to fixedly engage the second adapter.
The first adapter has an input end positioned proximately to the focus of the light source, the position where a maximum amount of light is coupled into the first optical waveguide. The first optical waveguide can be made out of a single fiber, a cladded rod, or a fused fiber bundle. In addition, the first optical waveguide can be tapered to allow matching of the input numerical aperture to the output numerical aperture or areas. The first adapter may have a first conical surface for contact to the housing of the light source system for alignment and heat sinking. The first adapter in one embodiment has a first detente to engage releasably a retaining structure, such as a spring-biased ball plunger, when the first adapter is positioned in the light source system.
The second adapter is designed to releasably engage the first adapter. In one implementation, the second adapter with a second input end is inserted into the opening of the first adapter such that the light exiting the first output end of the first optical waveguide is coupled efficiently into the second optical waveguide. The second optical waveguide can be made out of a single fiber, a cladded rod, or a fused fiber bundle. In addition, the second optical waveguide can be tapered for matching of numerical apertures or areas. The second adapter may also have a conical surface that mates with a cavity in the first adapter for alignment and heat sinking. The second adapter in one embodiment has a second detente to engage a retaining structure, such as a spring-biased ball plunger, when the second adapter is inserted into the first adapter.
The output end of the second adapter fixedly connects to the proximal connector on the output waveguide. For example, a screw or bolt may be used to attach the second adapter and the proximal connector. In this way, the application of an axial force causes the first adapter to release from engagement with the light source system or the second adapter to release from engagement with the first adapter while the second adapter and the proximal connector continue to be attached. As a result, the proximal end of the output waveguide is rarely exposed to contamination during normal use and handling.
In another embodiment, the output end of the second adapter consists of an output conical surface for alignment and heat sinking. The proximal connector on the output optical waveguide has a matching conical surface for close contact with the output conical surface of the second adapter. The light from the second optical waveguide is coupled to the output optical waveguide efficiently without a heat buildup. The output optical waveguide can be a single fiber or a fiber bundle. The materials can be made out of glass, quartz, or plastic. For high power applications, the output proximal connector and the output end of the second adapter can be made out of metal for good heat dissipation. For lower power applications where heat is not a concern, plastic output proximal connectors can be used for lower cost.
In one embodiment, the proximal connector has a slot that allows for the insertion of a clip, and the second adapter has a third detente that mechanically engages the clip when it is inserted into the slot in the proximal connector. In this way, the second adapter may rotate in relation to the output connector. In another implementation, the groove in the adapter is angled so that an inserted clip presses against the angled surface, resulting in a force to urge and hold the second adapter into proper position for optical connection between the first optical waveguide and the output optical waveguide. In particular, the second optical waveguide is placed in close proximity to the output waveguide to allow optical connection, but a separation between the second optical waveguide and the output waveguide is preserved in order to prevent heat transfer between the waveguides.